• Polymer(Korea)
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• v.26 no.5
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• pp.634-643
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• 2002

Ultrathin film of polyamic acid having benzene and sulfonyloxyimide moieties was prepared using the Langmuir-Blodgett (LB) technique, and then photosensitive polyimide LB film was obtained by the thermal treatment of precursor polyamic acid multilayers at 200$\^{C}$ for 1 hr. The polyamic acid was synthesized by condensation polymerization under THF and pyridine cosolvent. All monomers and polymers were identified through elemental analysis, FT-IR and $^1$H-NMR spectroscopic measurements. The microarray patterning of photosensitive polyimide LB film on a gold substrate was generated with a deep UV lithography technique. The well-characterized monolayer of cytochrome c was immobilized on the microarray patterns using two different self-assembly processes. Physical and electrochemical properties of the self-assembled cytochrome c monolayer were investigated based on cyclic voltammetry and atomic force microscopy (AFM). Also, its application in bioelectronic device was examined.

• Polymer(Korea)
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• v.30 no.4
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• pp.362-366
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• 2006

It was found by polarized FTIR spectroscopic studies that pentacene molecules are arranged with their molecular axes perpendicular to the substrate surface when pentacene films are deposited on a polyimide alignment layer. The ring plane in a pentacene molecule is arranged parallel to the rubbing direction of the polyimide alignment film while no specific arrangement of vertically deposited pentacene molecules was found for the film without rubbing. The pentacene band at $1296cm^{-1}$ which has a transition dipole moment parallel to the ring plane is much stronger in a polarized IR spectrum of parallel to the rubbing direction, whereas the band at $908cm^{-1}$ whose transition dipole align normal to the ring plane shows much stronger intensity in a spectrum of perpendicular to the rubbing direction. These findings indicate that orientation of polyimide chains affects the arrangement of pentacene molecules when they are deposited on a polyimide alignment film.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.506-509
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• 2004

We have investigated the generation of pretilt angle for a nematic liquid crystal (NLC) alignment with in-situ photoalignment method on polyimide (PI) surfaces using thin plastic substrates. The LC aligning capabilities and pretilt angle of the thin plastic substrates by in-situ photoalignment method were better than that of the glass substrate by general photoalignment. Also, the LC pretilt angle increased with increasing heating temperature and exposure time. And EO characteristics of photoaligned TN-LCDs using in-situ photodissociation method on glass substrate and on plastic substrate are also excellent.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.953-956
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• 2002

We successfully developed new photo-alignment materials which can be treated with linearly polarized UV (LPUV) light in near UV region. The alignment films were also shown to provide with surface anchoring as strong as that on rubbed polyimide when exposed to the LPUV light with warming up the substrate. It can be also able to control pretilt angle by introduction of alkyl side chain.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2014.11a
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• pp.16-16
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• 2014

본 논문에서는 polymer 기판 위에 direct inkjet patterning을 효율적으로 수행하기 위하여 기판 표면의 chemical bonding과 morphology를 in-line system 적용이 가능한 near atmospheric pressure plasma (N-APP)를 이용 하여 기판을 modifying 시켰다. modified substrate 위에 inkjet printing을 이용하여 metal interconnection을 하였다. 그 결과 기존 기판에서의 line width 보다 얇은 선폭을 획득 하였고 adhesion이 향상 되었다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.05a
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• pp.81-81
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• 2015

inkjet printing system으로 flexible 기판위에 metal interconnection 혹은 metal mesh를 제작 할 때 metal과 flexible substrate 의 접착력을 향상 시키고 선폭을 조절하기 위하여 surface roughness를 생성 시키고 표면을 hydrophobic 하게 개질 하였다. 그 결과 metal line의 선폭과 접착력이 향상됨을 알 수 있었다.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2001.11a
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• pp.171-177
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• 2001

The adhesion enhancement from inserting a RF bias-sputtered Cr layer between Cu and polyimide (PI) has been studied. The RF bias power applied in this study was ranged from 0 to 400 W. Without the RF bias, the peel strength, which measures the adhesion strength, was nearly o g/mm. As the RF power was increased, the peel strength rose up to ~130 g/mm at 200 W, which remained constant with further increase of the RF bias power. Cross-sectional transmission electron microscopy(TEM) was used to investigate the interfacial reaction between the Cr film and PI substrate during the bias sputtering. The Cr/PI interface without the application of RF dais showed a clean, sharp interface while the RF raised Cr/PI interface had about 10~30 nm thick atomistically mixed interlayer between the metal film and PI substrate. This interlayer appeared to have resulted from the implantation of high energy adatoms during the RF bias sputtering of Cr film. This mixed layer serves as an interlocking layer, which enhances adhesion between the metal and PI layers.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.1125-1131
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• 2004

We have investigated the generation of pretilt angle for a nematic liquid crystal (NLC) alignment with rubbing alignment method on the two kinds of polyimide (PI) surfaces using thin plastic substrates. The NLC pretilt angles generated on thin plastic substrates are higher than that on the glass substrate. We study that AFM (atomic force microscope) image of rubbed PI surface with polymer film has formed the micro-groove. Also, EO characteristics of the TN-LCD with a rubbed PI surface based on polymer are almost the same as that of the TN-LCD with a rubbed PI surface based on glass.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1624-1626
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• 1996

PoIyimide thin films fabricated at substrate temperature $20^{\circ}C$, $40^{\circ}C$and $70^{\circ}C$ by vapor deposition polymerization method were confirmed by FT-IR spectra. It is found that deposition rate decreas according as increasing substrate temperature. Defusion depth of evaporation Al at which thin films be used for an insulating films between layers of semiconductor were about $300{\AA}$.

• Polymer(Korea)
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• v.36 no.4
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• pp.486-493
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• 2012

Photocurable sulfonated polyimide (SPI) polyelectrolyte containing chalcone group was prepared and fabricated on an alumina electrode pretreated with chalcone-containing silane-coupling agent. SPI films with bis(tetramethyl)ammonium 2,2'-benzidinedisulfonate ($Me_4N$-BDS)/4,4'-diaminochalcone (DAC)/pyromellitic dianhydride (PA)= 90/10/100 possessed very linear response(Y = -0.04528X+7.69446, $R^2=0.99675$) and showed resistance changing from 4.48 to $2.1k{\Omega}$ between 20 and 95 %RH. The response time for absorption and desorption measurements between 33 and 94 %RH% was about 79 s, which affirmed the high efficiency of crosslinked SPI film for rapid detection of humidity. A negative temperature coefficient showing $-0.49%RH/^{\circ}C$ was found and proper temperature compensation should be considered in future applications. Moreover, pretreatment of the substrates with chalcone-containing silane-coupling agent was performed to improve the water durability and the stability of the humidity sensors at a high humidity and a high temperature and long-term stability for 480 h. The crosslinked SPI films anchored to electrode substrate could be a promising material for the fabrication of efficient humidity sensors with superior characteristics compared to the commercially available sensors.